Automatic-focusing camera.



J. BECKER.

AUTOMATIC rocusmc CAMERA. APPLICATION FILED AUG.26. 191|.

1,142,295. fatemi June s, 1915.

- :sinus-Suini.

i. BECKER. AUTOMATIC FOCUSINGA CAMERA.

APPLICTIGN FILED #06.26. QH.

Patented June 8, 1915.

T1 WMD) J. BECKER.

AUTGNIATIC FOCUSING Awucmon Fluff? AUG.

IAMEHA.

* is 15a 40cm correspond directly UNITED STATES PATENT oEEIcE.

JOSEPH BECKER, on WASHINGTON, DISTRICT oF- COLUMBIA.v

AUTOMATIC-FOCUSING CAMERA.

applicati@ ined August 26, 1911. serial No. 646,185.

To all whom, it may concern Be it known that I,1 Josnrn EcIIER, 'a

'citizen ofthe United States, residing at Washington, in the District of Columbia,

have invented a new .and -useful Improvement in Automatic-Focusing Cameras, of

whichthe following is a specification.

The present invention relates to automatic focusing cameras of the type disclosedd in my two prior applications, Case K and Case O, Serial Nos. 269,048 and 542,842, respectively,`iled July 10, 1905, and- February 9, 1910; and it is based on my discovery that a perfectly circular'cam Orsimple eccentric may serve as focusing gear either in place of, or in .coperation with, the focus- Y ing linkages of the said priorl applications, Cases K and O' which have since become Patents 1,103,342 and 1,103,343. The present application has Vvbeen identified for convenience of cross reference as Case T. y

In the accompanying drawings-Figure 1 is a vertical longitudinal section of a camera similar in all essential features to the camera shown in Figs.l 19 to 22 of the said prior applications, but specially adapted to be actuated by an eccentric 1nstead of by a linkage. 4Fig. 2 is. a plan of the said eccentric with a diagram of the connections between it and the four focal planes P, F, F', P of the camera. Fig. 3. is adiagram' to illustrate 'the geometrical principles involved'. Fig. 4 is a partly diagrammatic illustration of a conplete form in which the mechagrams all drawn to the scale shown under eferringfto Figsfl and 2, the bed of the` camera comprises two parallel rails 11 mounted on and firmly connected with a heavybase 1-2 by means-of two end supports 13 which are bolted to the base 12 by .four bolts 14 aud riveted to the'rail ends. Only oneof the two supports 13, one of the four fasteningbolts 14v and one of the two rails.

11 can be seen in the drawing.

At their middle part the rails 11 are connected by a cross bar 16, which is perforated. vertically at its middle point, and this bore simple 15 is continued through the base 12 to form in the radial slideway 40`of .a circular disk V19 Whose eometrc centeris indicated by the-dot C, 1g. 2. Disk 19 may be'clamped on arm18 in any desired radial adjustment by tightening lthe clamp screw 20 which is threaded into arm 18, but passes freely through the clamping jaw 21. The disk 19 is, furthermore, provided with a peripheral cylindrical flange or rim 22 which engages with the correspondingly curved jaws' 23 of the pintle 24 on one side and pintle 34 on l I Speccaton of Letters Patent. Patented J 1168, 1915.

arbearing for a pintle 17 which is riveted lto a'radialarm 18. Thisy arm 18 fits smoothly the other. vPintle 24 is/revolubly held in carriage 25 by a split-*Din 26 'so that its jaws mayslightly" turn to follow the varying inclinations ofthe revolving cam rim 22, and it-A is adjustably-connected with the object frame O by a clamp bolt 27 ,'as fully set forth in said prior applications.'` Pintle 34 is]A similarly -held .in carriage 35 by .a ,split pin 36 and is adjustably connected with the image frame I by a cla-mp -bolt'37 The pintles 24 and 34 are setj or adjusted in properrelation to their respective frames by focusmg on niintytas fully explained in my said two prior applications and the connecting gear is'adjusted,.also as in the said' prior applications,.b ,1` focusing one of the two end frames I or O ori the other.

In the present instance the focusing of I on C or of 0 on IV is most easily performed by adjusting the eccentricity CDof the eccentric. This adjustment canI be made in any angular position of the disk 19, but it is most easily done by first setting the disk 19 so that-its center C shall lie in the plane determined by the axes A, D, A of the three pintles 24, 17 and 34.` This sets and holds the two end frames .O and I at their greatest separation when they must. yield the greatest possible enlargement; if C be.

set between D and A", as shown in Fig. 2;

' or the corresponding smallest possible rcductiorn if C be set between D and A.

` Having loosened clamp'screw 21, thetwo end frames O, 1 with the annular rim connecting themV are slid along longitudinally while the lens frame L -remains siationary, and in Athis manner one of the cnil frames may be focused on thc other while the same movements properly vary the eccentricity CD of the eccentric by moving center C with relation to axis D.

lVhen the sharpest focus` has been obtained, clamp screw 21 is tightened and the ycopying factor n to vary from its maximum l value down through all intermediate values to the minimum, land that during this half turn the upper half'of `the ,canr strictly belongs to the image plane P, whereas the lower half belongs `to the object. plane P. The cam disk 19 is, therefore, really composed of two distinct cams, afact that will become still more evident in considering the complete form o f Figs. 8 to 10. f

Theory of the dem'ce.-The vaxis D of the eccentric shaft 17 may be considered as being directly and invariably'connected'with 4the principal focal planes F, Fof the lens by stays x, x', as indicated in Fig. .2, Similarly, the axis A of pint-le 24 is virtually lconnected to the object plane P by a bar of-length m; and axis A; of pintle 34 tjo the image plane P by a bar of length m. v

In focusing on infinity, as will-be seen on referring to the said prior applications, m and m are adjusted tobe precisely equal .to ac and and as a result the variable lengths AD, DA and PF, FP are connected by the equations PF=AD (1) FP=D A (2) in which the values AD and DA are varied and determined v mechanically by: the disk.19, which may be considered (Fig. 3) as a perfeet circle of radius CAgr-f' pivoted at D.

`When the eccentric is set as in Figs". 2, AD and DA are,lrespectively, equal tothe segments A,D and DA1 of the longest or diametral -chord A,A, in Fig. 3; and the operation of focusing the one 'endl-frame on the fsther has made the product PF.FP or its equivalent, AD.DA equal to f2. (the second power of the focal length ofthe lens).

Revolving the eccentric of Fig 3 to bring chord A'AZ into the ,camera axis changes the values of AD and DA to AZD and DA2 and, in View of what precedes and of awell known proposition of geometry, we have chord AxA which is perpendicular to the diametral chord and is divided by D into equal segments so that these segments must each l be equalI to f. It is, therefore, seen that the adj ustment of the eccentricityA e (Fig. 3) *hasA simply setthe eccentric lto make one-half of Icopying factorby n(m.)and its minimum va Y' e by non...) 'We have Complete f0rms.-The exact operation of the device is most easily understoodin what 'I designate as my complete/forms. Fig. 41

is a partly diagrammatic illustration of a cbmplete for'm corresponding to the complete form shown in Fig. 3 of the said prior applications.

f are.-

Here two equal eccentries 50, 51 connected to revolve together by the object plane Pand'eccen'tric 51 directly on an axis A in vthejimage plane P. A bar 55 is shown to represent the bed and slideways of the camera. The copying factor in Fig. 4f is equal to 2.

i Fg. 5 shows the displacements produced in Fig. 4 by turning the eccentrics clockwise through one-half of a rightangle, which changes the copyingfactor from'2 to 1.662,

or approximately five-thirds.

Fig. 6 shows the displacements in Fig. 4 by turning the eccentrics through a full right angle, the copying factor being reduced to 1. .y

The passage from the complete form,'Fig. 4, to the simplest form, Fig. 7, involves produced' three stages illustrated in Figs'. 8, 9 and 10 in which unnecessary parts of the cams G0,` 61 are suppressed for clearness.

`The dimensions in Figs. 8 to 10 are:

Moreover, we have, in Fig. 8,- `CCDD l=`28 em.

"age equivalent of the camk gear. Fig. 8 is directly comparable withFig. 3 of my said Case K, now Patent 1,103,342, where the short links BD, BD correspond, respectively, to the 'eccentricity CD, C'D of the present cams. In my said Casel K the. simple form, Fig. 4, is derived. from the'complete form, Fig. 3, as explained on page .3v

of the Patent 1,103,342, by shiftingl the triangle ABD to the right, and thetriangle ABD to the left in such manner as to preserve the. equality of the Newtonian s ace elements in equations 2 and 3 of said ase K. This shifting of the Newtonian space elements AD, DAf of the mecha-msm with relation tothe respectively equal- Newtonian space el ments PF, FP. of the-lens applies here as n said Case K. -Inpresent Fig. 9 the necessarily equal. shifts of4 terminals A and D are,'respectively,' measured by-m and PF is dependent uponhavingat least one m; and the necessarily 'equal shifts of terminals A and' D are, respectively, measured y m and As in said Case K 'the 'equali y of the Newtonian space ^elements AD and of the terminals A or D freely adjustable 'v 1 andthe equality ofthe Newtonian space elements DA and FP is dependent.. upon .raving at least one o'f `the terminals' A or'D nreely adjustable; and the equality is prefsrably obtained here as in .Case -K by focusfng on right infinity for AD, and on left infinity for AD. This'is--very--clearly set.

forth in present Figs. 12 to' 15, where the i lens FNNF and the Newtonian spaces IF, v

FP of the lens are the sameyas in present Figs. 8 to 10. Each of the'seven longitudinal space elelnents m, at, 'rn/,.w, AD, DA and DD that must be accounted for in the mechanism is brought into. evidence by having assigned to it a finite/positive whole number value which is the same inthe. four Figs. 12 to 15;-but the Newtonian spaces l -AD, DA of the mechanism are purposely shown out of adjustment.` Instead therefore of having m equal :v and mf equal m', `we have m; 4 cm. 8 cm. 'rn/:'12 cm.

Now, tomake AD must be reduced vby 4 centimeters, and this reduction 'can be' made by adding 4 cm. to m or by subtracting 4 cm. from Hence either m, or a: must be adjustable in length.

At the right the Newtonian space D. A of the mechanism must Abe made, 6 centimeters longer, and. this can -be done by shortening m to make it equal to m or b lengthening to make it equalto m. ence the principle established in my said Case K, that at least .two of the-connecting points must each be freely adjustable onits respective object, lens or image frame.

In Fig. 12 'the imanginary bars m and m are supposed to be the adjustable bars; .and the imaginary bars v'and are supposed to be invariable in length or non-adjustable; 'and these non-adjustable bars, :v are shown black to distinguish themvfrom the adjustable barsm and m left white.

In Fig. 13 the adjustable or white bars are! m and.a:,' in Fig. 14 theyare .fr and w; and in Fig. 15 they are-:v and m- InFig. 12the 2 independently adjustable' equal PF, space AD terminals are A andv A iri- Fig. 13 they are A and D', in Fig. 14 they are D and D';

in Fig. 15- the .are-D and A. VV-hereter-l minals D an D are merged in a single terminal DD as in the simple forms the 2.

adjustable. terminals may be either A and'A or A and DDor .DD and A..

I'have stated above in describing the ad.- justment of l-that the adjustment in eccentricity, or determination of dimension -CD, coul'dbe'm'adein any angular position of disk 19. This is made clear .in the diagram igu're, Fig. 11, where the terminals A .and A are supposed to 'have finally been brought into the relative fposition illustrated,-

first, by' focusing on le ininity,l then by focusing on right infinity; thirdly, by focusg P on P', exactly as in my said Case K. ixii order thatthis last or thirdfocusing op- -eration shall be as free as possible, to be Amade' at any preferred copying factor, as in Case K, it is. better to disconnect the cam ventirely at D. In focusing .Pyon P the radialjslot 64 of the calm-62 will then generally be thrown off to one side, as shown, but, as the end frames' are temporarily clamped in their last focused relation, the terminals A and A will holdthe center C of the disk 62j in fixed position so that the disk 62can be slid around in termmals A and A as if really pivoted at C. `By thus turningv the' disk, counterclockwise in the case illustrated, "the radial slot 64 is easily broughtl back' into registration with the bore of pin D to be rigidly connected to pin D. Theadjustment is now complete and the temporary, clamps used onthe 'end frames canberemovedff". j

` A .diiculty tobe grasped is that the lbf) AD mdrr (if DI'A'famijivfrisoieiy` connections m V and or' 'in/"and m isi-'solely dependent uponv the: equlityofthe variable thatisucheq'ualities .'a-rfenot ina'ny Way dependent upon the type or form offconsta-nt product Afocusing mechanism -that I 'n'afv 5' be used toconnect-tlieterminals A, `D, DA", :A L Thisv can' easily be. proved in' F1 12 with A the-aid @tithe two Aaux'iliaiiy. varia lesa and Variable z i'stlie variable 'distance of terminal A from the Ier-tical orfo'cal plane F' and always remains-equalfto the difference (viz-a2) that exists betiveen'-thev rigid connections mandl @,'jandtli'i's -dierene' is constant Afor all values ffz'asf-long as. no cliange-is made.

'tween'tlfierigid connections 'in' `and and this difference is constant' orJall va-iue's'of al Y:is-long as' no change is made inthe said i 4enlargingcamera as aj'constituentyait of automatic focusiigiii'echaiiisiii bi-it'tlie said l' two-cams are', intended' vto4 'ac t 'inlopi'iositioii on the same en lfi-aiiie ofi-the calimera," 't l i C one cam fof reid'ucej the distan'ceffroii'isuch endl frame to the lens fi1aiiije,""aiid"'tli `efot-lier anice," vThis Frcot rigid' connections/mf andan.

TheV constant 'difference` of' equation 7ji's uil; .when thev terminals 1A i .and 'il fare in proper-adjustment and it is finite when the same vterminals D- are 'outoff adj 'ustment Theco'nstant difference of; equation 81:1smlf vwhen terminals D andiAvf-are in-'proper adjustmentandrit is `{inite'fwhen tlief's'ame terminals D', A areoi'itl-of"adjustment;

erly adjusted,

`Norv the lsolepurpose o'fyhanvingi twoiof 8 separatei)V equal to equality of therigid connections iiiiplies 0 andxai-iabieg is iai-egvariabieidistancef -iilwliti' 0f flicwtwiwri SimCeSfiuid "im" of terminal ik". 'from Atiie 'Ii'e'rtial or'f'ocal in aie-:said :pig-ia @Gangesthe' icio' their respective frame O, L, I is to maketiiese constant differences ofequations 7 and i zei-0 se tliatweshall have, as in Figs. 1,

Alt either 'end offtlie 'caiii'erm-therefore,

reisa, so that-.adiistiiig'to secure tlieoiie equaiity seein-,es both.- ffli'is is probablr the simplest possible expiaiia'tioii of the. priii- "i ciple that is iiiiol'i'etl inthe seiieral methods of adjustment u lii'ch 'ii'ere first disclosed iii my said Case ii, noir Pritei'itlLilO, and which is simply rea ip liegl herein for-,use

with a`di'teienttipe vof 'const-ant product" mechanism'.f i

Note 1 Inallffornis sho :vntheleiisf'jaiiie L is supposed 'tot be 'tlie-statioiiar513f iiiie, but the mecharisiii"'determines the re itire positions o f'the -tlireefiamesgregaiggll,fs of Vwhat maybe the "absolute-indientotany one Y a ils of the cainei"'af `lied,Y 1p rovided' the eccentric axis D or .axes VD," D' hedire'ctlyinoiiiited' ed on the Asaine:verticalimiti-s' to be used-'iii :iii

sire to securebiy Letters Patentis l automatic focusing iiiechanisiii 4for. c 'aiu'sii'ig two of the said threesupports'to more with relation to the third` to 'produce dcsireu changes in the size of thevsharplfxr focused" image; such focusing mechanism coiiipiising: first. a rotary cam fact-curud to coiiferm with a vplane curve aiidjhaviiig its axis of rotation located to deteriiiinee series of varying radius vectors for varying thesepf moondly, a rotary' carri face curved to conform vwith a plane curve 'and havingits axis i of natation located-to determine a series of varying radius vectors for varying the sep-A aration of the said lens and image supports; thirdly', connections between the two, cam

has for causingthemto rotate simultaneonsly so, that the angularly corresponding vectors of the -two cam faces shall `be brought into action at the sam'ev time.

2, The combination with a photographic' amera, comprising an ,object support, a

automatic focusing mechanism for causing two of the said vt ree supports to move with relation tothe hird, `to produce desired changes in the size of the sharply focused image; such focusing mechanism comprising: first, a. rotary cam faoecurved to conform with a plane curve and'having its axis of rotation locatedto determine a series' of var'ving vectors f a varying the separation ondly, a rotary'cam facecurved-to conform with a plane curvea'nd having its axis'of rotation located, to determine a series of adapted v'to guide two of said supports with relation' to the third, of a rotary cam plate having-its axis mounted perpendicularly to theV direction of the -'ways in fixed relation to the lens support and adapted to act withV opposite cam faces -on the said object and ima e supports to move them simultaneously wit relation to said lens support.`

4;. The combination with' a'photographic camera, comprising a lens support,.an image support,- and an object support, and ways vadapted to guide two of said supports with relation to the third, of a plane cam plate eccentrically pivoted in fixed .relation to said lens support and adapted to act with opposite cam faces on said other two supports.

5.- The combination. with a photographic camera, comprising a lens support, an image support, and an object support, and ways lens support and anA image support; also' of the said object and lens supports; sec-,

adapted to guide two or said supports with' nntlon of the sald ob]ect and lens supports;

relationto the third, ofV a pla'ne cam plate' eccentrically pivoted in fixed relation to said-l lens support'and adapted to act with opposlte'cam faces on said other two supports, the degree of eccentricity of said eccentric being adjustable.

6; The' combination with' a photographic camera, comprising a' lens support, an image support, and an object support', and ways-70 adapted t0 guide ltwo of said supports with relationv to the third, .of anl eccentrically pivotcd circular cam pivotally mounted with relationl'to the said lens support and adapted to act, with one varying radius vector, on the said'object support, and with the oppositely directed co-varying radius, vector on .the said image support.

7.V The combination with a photographic camera, comprisinga lens support, an object Support.' and an -imagesupporhand ways.

'adapted to guide two offsaid supports with relation to the third,of a cam face curved to conform with a plane curve having a varying radius vector-for varying .the separation vof the said object and lens supports; and a cam face curved to conform with a planey ,curve having a varying radius vector for varying the-separation of the said lens and image supports; andv'connections to cause such two cam faces to rotate simultaneously; said cam faces having their angularly corresponding Vvectors proportioned toA form a constant product. Y A

8. The combination witha photographic camera, comprising a lens support, an. object support and an image support, and ways adapted to guide two of said supports with Y relation to the third, of a cam face curved to conform with a plane curve having a vary- 100 ing radlus vector for varying the separation 'of the said object and lens supports; anda cam' face curved to conform with a plane v curve having a varying radius vector for varying the separation of the said4 lens and 105 image supports; and connections Vito cause such two cam faces to rotate simultaneously; `said cam faces having their angularly'c'orref spending vectors proportioned to form a constant product; 'also adjustments to per- 110 mit of changing the vector lengths and value of'such constant product as may be required for different lenses.

In vtestimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses. y

JOSEPH BECKER.

Witnesses:

CLARENCE MILLER,` H. P. HOWARD, Jr. 

